Project description:Preterm neonates are susceptible to gastrointestinal (GI) disorders such as necrotizing enterocolitis (NEC). Maternal milk, and especially colostrum, protects against NEC via growth promoting, immunomodulatory and antimicrobial factors. The fetal enteral diet, amniotic fluid (AF), contains similar bioactive components and we hypothesized that postnatal AF administration would reduce inflammatory responses and NEC in preterm neonates. Thirty preterm pigs (92% gestation) were delivered by caesarean section and fed total parental nutrition (TPN) for 48 h followed by enteral porcine colostrum (COLOS, n=7), infant formula (FORM, n=13) or formula + porcine AF (AF, n=10). Using a previously validated model of NEC in preterm pigs, we determined the structural, functional, microbiological and immunological responses to AF when administered prior to and after introduction of a suboptimal enteral formula diet. Keywords: Healthy versus inflammed tissues in relation to necrotizing enterocolitis
Project description:Preterm neonates are susceptible to gastrointestinal (GI) disorders such as necrotizing enterocolitis (NEC). Maternal milk, and especially colostrum, protects against NEC via growth promoting, immunomodulatory and antimicrobial factors. The fetal enteral diet, amniotic fluid (AF), contains similar bioactive components and we hypothesized that postnatal AF administration would reduce inflammatory responses and NEC in preterm neonates. Thirty preterm pigs (92% gestation) were delivered by caesarean section and fed total parental nutrition (TPN) for 48 h followed by enteral porcine colostrum (COLOS, n=7), infant formula (FORM, n=13) or formula + porcine AF (AF, n=10). Using a previously validated model of NEC in preterm pigs, we determined the structural, functional, microbiological and immunological responses to AF when administered prior to and after introduction of a suboptimal enteral formula diet. Keywords: Healthy versus inflammed tissues in relation to necrotizing enterocolitis Pigs from each treatment group (COLOS, n=4; FORM, n=6; and AF, n=7) were randomly selected for microarray analysis of frozen distal small intestine samples. The FORM group was further divided into formula-fed healthy pigs (F-HEA, n=3) and formula-fed NEC pigs (F-NEC, n=3) in order to compare sick versus healthy formula fed pigs. Equal amounts of total distal small intestinal RNA from all pigs were pooled to make the reference sample. Samples and reference pool were labelled with Oyster 550 and 650, respectively. The in-house spotted porcine oligonucleotide microarray version 4 (POM4) is a low density microarray consisting of 384 different oligonucleotide probes representing more than 200 different immune related genes.
Project description:Chorioamnionitis (CA), resulting from intra-amniotic inflammation, is a frequent cause of preterm birth and exposes the immature intestine to bacterial toxins and/or inflammatory mediators before birth via fetal swallowing. This may affect intestinal immune development, interacting with the effects of enteral feeding and gut microbiota colonization just after birth. Using preterm pigs as model for preterm infants, we hypothesized that prenatal exposure to gram-negative endotoxin influences postnatal bacterial colonization and gut immune development. Pig fetuses were given intra-amniotic lipopolysaccharide (LPS) 3 d before preterm delivery by cesarean section, and were compared with litter-mate controls (CON) at birth and after 5 d of formula feeding and spontaneous bacterial colonization. Amniotic fluid was collected for analysis of leukocyte counts and cytokines, and the distal small intestine was analyzed for endotoxin level, morphology and immune cell counts. Intestinal gene expression and microbiota were analyzed by transcriptomics and metagenomics, respectively. At birth, LPS-exposed pigs showed higher intestinal endotoxin, neutrophil/macrophage density and shorter villi. About 1.0% of intestinal genes were affected at birth and DMBT1, a regulator of mucosal immune defense, was identified as the hub gene in the co-expression network. Genes related to innate immune response (TLR2, LBP, CD14, C3, SFTPD), neutrophil chemotaxis (C5AR1, CSF3R, CCL5) and antigen processing (MHC II, CD4) were also affected and expression levels correlated with intestinal neutrophil/macrophage density and amniotic fluid cytokine levels. On day 5, LPS and CON pigs showed similar necrotizing enterocolitis (NEC) lesions, endotoxin levels, morphology, immune cell counts, gene expressions and microbiota (except for difference in some low-abundant species). Our results show that CA markedly affects intestinal genes at preterm birth, including genes related to immune cell infiltration. However, a few days later, following the physiological adaptations to preterm birth, CA had limited effects on intestinal structure, function, gene expression, bacterial colonization and NEC sensitivity. We conclude that short-term, prenatal intra-amniotic inflammation is unlikely to exert marked effects on intestinal immune development in preterm neonates beyond the immediate neonatal period.
Project description:Necrotizing enterocolitis (NEC), a serious gastrointestinal disease that afflicts 5-10% of preterm infants, often progresses rapidly from mild food intolerance into extensive haemorrhage, inflammation and necrosis. Events leading to NEC have remained poorly defined. Similar disease characteristics are observed in preterm pigs 24-48 h after feeding formula. Using this model, we aimed to characterize the temporal development of NEC, and describe the functional and immunological response of the preterm intestine preceding NEC. Keywords: time course
Project description:Large White and Meishan pigs were either non-treated or injected with mammalian 1-24 ACTH (Immediate Synachten, Novartis France) at the dose of 250 µg per animal. Pigs were sacrificed either immediately after capture from their home cage (non-treated animals) or 1 hour following ACTH injection. Adrenal glands were immediately collected from pigs and frozen on dry ice and then stored at -80°C until RNA isolation. Keywords: stress response, adrenal, gene expression, pig
Project description:91 preterm infant gut metaproteomes measured in technical duplicate using an eleven salt pulse 2D-LC-MS/MS method. Samples represent 17 preterm infants over the first several weeks of life, of which 6 preterm infants eventually developed necrotizing enterocolitis.
Project description:Regulatory Mechanisms of Atrial Remodeling of Mitral Regurgitation Pigs This study enrolled 6 pigs (age: 18 months) and divided into three groups: mitral regurgitation pigs (MR) (n = 2; 2 males sacrificed 12 months after surgery), MR pigs treated with valsartan (MRV) (n = 2; 2 males age-matched to MR sacrificed 12 months after surgery), and normal control pigs (NC) (n = 2; 2 males age-matched to MR pigs). Valsartan (3.43 mg/kg/day), a type I angiotensin II receptor blocker, was administered from one week before surgery and then daily after surgery in the MRV group. We sought to systemically elucidate critical differences in the alteration of RNA expression pattern between the atrial myocardium of pigs with and without MR, and between the atrial myocardium of MR pigs with and without valsartan using high-density oligonucleotide microarrays and functional network enrichment analysis.
Project description:Large White and Meishan pigs were either non-treated or injected with mammalian 1-24 ACTH (Immediate Synachten, Novartis France) at the dose of 250 µg per animal. Pigs were sacrificed either immediately after capture from their home cage (non-treated animals) or 1 hour following ACTH injection. Adrenal glands were immediately collected from pigs and frozen on dry ice and then stored at -80°C until RNA isolation. Keywords: stress response, adrenal, gene expression, pig 47 samples